At the moment the conveyor reaches the filling station, the PLC reads the presence of a bottle through a proximity sensor and immediately opens the corresponding solenoid valve to dispense liquid. The AMK input‑output card provides the plant operator with the physical interface that translates the sensor’s voltage change into a digital signal for the controller and supplies the necessary drive current to the valve. Because the card houses both input and output channels on a single board, the operator can wire the sensor and the valve side‑by‑side, reducing panel space and simplifying troubleshooting. When a fault occurs, the card lights an indicator and isolates the affected channel, allowing the operator to identify a clogged valve or a failed sensor without stopping the whole line. The same board is often installed in batch‑mixing plants, where it links level switches to pump control relays, giving operators real‑time feedback on material levels. By placing the card directly in the control cabinet, the operator gains immediate, reliable control over critical on‑off actions that keep the process flowing.